Modern open plan offices are provided with work areas that are partitioned by panels which generally have a height less than the height of the ceiling. The panels and ceiling are sometimes acoustically engineered to absorb the vocal and machine noise attendant to common office activity, but not all of these sounds can be eliminated by acoustical engineering and so noise distraction remains a problem.
With respect to speech, it is not the loudness of the speech that causes the greatest distraction, but the fact that the speech can be understood. Thus, a sound system which can generate a masking sound signal which decreases the understandability of speech without itself becoming an annoyance or just background sound is desirable.
Effective masking sound systems have heretofore generally been designed specifically for the particular office area in which they are located and as such are costly. The majority of these systems are installed in the ceiling and become a permanent fixture of the office. This poses a special problem to users of office space, because in addition to the high installation cost, additional sums must be expended to tailor the sound system to area by area needs or to move the system if vacating the premises and even if it is removed, the system may not be adaptable to other office areas. Also, specially designed sound systems can involve high maintenance costs, since personnel trained in servicing such specially designed equipment may be difficult to find.
Portable sound masking devices are also known in the art. However, these devices produce a continuous sound spectrum which may be ineffective, monotonous and more annoying than the sounds that are masked.
Therefore, it is an object of the present invention to provide a self-contained masking sound generator unit which masks undesirable sounds found in the vicinity of the unit.
It is still a further object of the present invention to provide a masking sound generator which can be readily installed in various locations based on the need of the user.
It is still a further object of the present invention to provide a masking sound generator that can be adjusted by the user to conform to the specific sound signals present in the vicinty of the unit.
It is still a further object of the present invention to provide a masking sound generator that produces a sound signal having subtle wave variations to thereby provide a pleasant natural sound characteristic which effectively masks other sounds located in the vicinity of the unit.